Films with stress relief intra-chamber seals

ABSTRACT

The present disclosure relates to an inflatable cushion including a first film ply and a second film ply that is sealed to the first ply. The first and second plies can define an inflation chamber therebetween that can be inflatable with a fluid and operable to contain the fluid. An interior seal can be disposed within the inflation chamber attaching the first and second plies together. The interior seal can include a perimeter seal that encloses an inner portion in which the first and second plies are unattached from one another.

RELATED APPLICATIONS

The present application claims priority from U.S. Patent ApplicationNos. 61/944,515, filed Feb. 25, 2014; 62/077,815, filed Nov. 10, 2014;and 62/103,504, filed Jan. 14, 2015, the disclosures of which areincorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure is directed to flexible structures that may beinflated and used as cushioning or protection for packaging andshipping.

BACKGROUND

A variety of inflated cushions are well-known and used for sundrypackaging applications. For example, inflated cushions are often used asvoid-fill packaging in a manner similar to or in place of foam peanuts,crumpled paper, and similar products. Also for example, inflatedcushions are often used as protective packaging in place of molded orextruded packaging components.

Generally, inflated cushions are formed from films having two plies thatare joined together by seals. The seals can be formed simultaneouslywith inflation, so as to capture air therein, or prior to inflation todefine a film configuration having inflatable chambers. The inflatablechambers can be inflated with air or another gas or thereafter sealed toinhibit or prevent release of the air or gas.

Such film configurations can be stored in rolls or fan-folded boxes inwhich adjacent inflatable cushions are separated from each other byperforations. During use, a film configuration is inflated to formcushions and adjacent cushions or adjacent stands of cushions areseparated from each other along the perforations.

A variety of film configurations are currently available. Many of thesefilm configurations include seal configurations that tend to wastematerial, inhibit separation of adjacent inflated cushions, and/or forminflated cushions that are susceptible to under-inflation or leakage,thereby inhibiting utility.

The films are typically inflated by being pulled from a bulk quantity ofthe film and passed over or proximal to a nozzle. The nozzle blows airin between the films forming cushions. Heat is then used to bind twoplies of the film together forming a seal which limits air fromescaping. Frequently the films are poorly aligned or have too muchfreedom (e.g. slack) to be efficiently delivered to the nozzle forinflation. Additionally, due to the heat and pressures used in theprocess, the films may stick to machine surfaces or the plies may bepulled apart while still hot and exiting the mechanism.

SUMMARY

In one embodiment, the present disclosure relates generally to aninflatable flexible structure. The inflatable flexible structure maycomprise a first film ply. The inflatable flexible structure maycomprise a second film ply that is sealed to the first ply to define aninflation chamber therebetween that is inflatable with a fluid andoperable to contain the fluid. The inflatable flexible structure maycomprise an interior seal disposed within the inflation chamberattaching the first and second plies together, the interior sealincluding a perimeter seal that encloses an inner portion in which thefirst and second plies are unattached from one another.

In various embodiments, the perimeter seal may entirely enclose theinner portion, separating the inner portion from the inflation chamber.The interior seal may be disposed within the inflation chamber. Theinterior seal may be disposed entirely within the inflation chamber. Theinterior seal may include a first elongated portion extending from theperimeter seal. The interior seal may include another perimeter seal.The first elongated portion may extend from the perimeter seal to theother perimeter seal. The interior seal may include an intersectionbetween the perimeter seal and the elongated portion, such that theintersection has three leg portions which are part of the perimeter sealand the elongated portion, the interior seal having an increased widthat the intersection compared to the perimeter seal and elongatedportion, thereby forming a gusset that resists localized stresses in thesealed film plies. The interior seal may include a second intersectionbetween the perimeter seal and a second elongated portion, such that thesecond intersection has three second leg portions which are part of theperimeter seal and the second elongated portion, the interior sealhaving an increased width at the second intersection compared to theperimeter seal and second elongated portion, thereby forming a secondgusset that resists localized stresses in the sealed film plies.

In various embodiments, the first elongated portion may extend from theperimeter seal to a second perimeter seal, and wherein the secondelongated portion extends from the perimeter seal to a third perimeterseal. The inner portion may be at least 10 times wider than theelongated portion. The inflatable flexible structure may include aplurality of said interior seals. The first and second plies may besealed to one another to define a plurality of inflation chamberstherebetween, the plurality of inflation chambers including theinflation chamber and a second inflation chamber. The second inflationchamber may include a second interior seal attaching the first andsecond plies together. The second interior seal may include a secondperimeter seal that encloses a second inner portion in which the firstand second plies are unattached from one another. The inner portion maybe configured to remain uninflated when the inflation chamber isinflated with the fluid. The first and second plies may be heat sealedtogether to form the interior seal. The first and second plies may besealed together with an adhesive to form the interior seal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-D are schematics of various embodiments of flexible structuresas used in conjunction with an inflation and sealing device;

FIG. 1E is a partial view showing an interior seal of FIG. 1C shownalong view II-II;

FIG. 1F is a partial view showing an interior seal of FIG. 1C shownalong view III-III;

FIG. 2 is perspective view of an inflation and sealing device inaccordance with various embodiments;

FIG. 3 is a perspective, exploded view thereof;

FIG. 4 is a top, right-side view as seen along axis Y of a materialsupport thereof;

FIG. 5 is a right-side view of a partially assembled system thereof;

FIG. 6 is a front view of the partially assembled device of FIG. 5;

FIG. 7 is a perspective, exploded view of a material support and brakeof the device of FIG. 2;

FIG. 8 is a right-side view of the material support and brake of thedevice of FIG. 2;

FIG. 9 is a right-side view of a sealing mechanism of the device of FIG.2;

FIG. 10 is a front, right perspective view thereof;

FIG. 11 is a front, cross-sectional view of post-sealing controlelements taken along line XI-XI of FIG. 9; and

FIGS. 12A-B are a perspective view of a film structure that forms acontainer.

DETAILED DESCRIPTION

The present disclosure is directed to flexible structures that may beinflated and used as cushioning or protection for packaging andshipping. Specifically, mechanisms prior to sealing and inflation andmechanisms post-sealing and inflation may improve the overall efficiencyand speed of the process of forming the cushions. Prior to sealing andinflation, the system may include a material support element whichbetter stores, controls, and delivers the material to the sealing andinflation mechanisms. After the sealing and inflation of the material,material control elements may better direct the material out of thesystem without damaging the seal or failing to release the heatermaterial from the contact surfaces.

Illustrative embodiments will now be described to provide an overallunderstanding of the disclosed apparatus. Those of ordinary skill in theart will understand that the disclosed apparatus can be adapted andmodified to provide alternative embodiments of the apparatus for otherapplications, and that other additions and modifications can be made tothe disclosed apparatus without departing from the scope of the presentdisclosure. For example, features of the illustrative embodiments can becombined, separated, interchanged, and/or rearranged to generate otherembodiments. Such modifications and variations are intended to beincluded within the scope of the present disclosure.

FIGS. 1A-1D illustrate schematics of various embodiments of flexiblestructures. The flexible structures may be formed in a variety ofmanners such as flexible structure 1040 shown in FIG. 1A, flexiblestructure 1042 shown in FIG. 1B, flexible structure 1044 shown in FIG.1C, or flexible structure 1046 shown in FIG. 1D. The flexible structure,such as a multi-ply web 100 of film, for inflatable cushions isprovided. The web includes a first web film layer, or ply, 105 having afirst longitudinal edge 102 and a second longitudinal edge 104, and asecond web film layer, or ply, 107 having a first longitudinal edge 106and a second longitudinal edge 108. The second ply 107 is aligned to beoverlapping and can be generally coextensive with the first ply 105 (asshown in FIGS. 1A-1D), i.e., at least respective first longitudinaledges 102,106 are aligned with each other and/or second longitudinaledges 104,108 are aligned with each other. In some embodiments, thelayers, or plies 105, 107, can be partially overlapping with inflatableareas in the region of overlap. The plies 105, 107 may be joined todefine a first longitudinal edge 110 and a second longitudinal edge 112of the film 100. The first and second plies 105,107 can be formed from asingle sheet of web material, a flattened tube of web material with oneedge slit, or two sheets of web material. For example, the first andsecond plies 105,107 can include a single sheet of web material that isfolded to define the joined second edges 104,108 (e.g., “c-fold film”).Alternatively, for example, the first and second plies 105,107 caninclude a tube of web material (e.g., a flatten tube) that is slit alongthe aligned first longitudinal edges 102,106. Also, for example, thefirst and second plies 105,107 can include two independent sheets of webmaterial joined, sealed, or otherwise attached together along thealigned second edges 104, 108.

The web 100 can be formed from any of a variety of web materials knownto those of ordinary skill in the art. Such web materials may includeethylene vinyl acetates (EVAs), metallocenes, polyethylene resins suchas low density polyethylene (LDPE), linear low density polyethylene(LLDPE), and high density polyethylene (HDPE), and blends thereof. Othermaterials and constructions can be used. The disclosed web 100 can berolled on a hollow tube, a solid core, or folded in a fan folded box, orin another desired form for storage and shipment.

As shown in FIGS. 1A-D, the web 100 can include a series of transverseseals 118 disposed along the longitudinal extent of the web 100. Eachtransverse seal 118 extends from the longitudinal edge 112 towards theinflation channel 114, and in the embodiment shown, toward the firstlongitudinal edge 110. Each transverse seal 118 has a first end 122proximate the second longitudinal edge 112 and a second end 124 spaced atransverse dimension d from the first longitudinal edge 110 of the film110. A chamber 120 is defined within a boundary formed by thelongitudinal seal 112 and pair of adjacent transverse seals 118.

Each transverse seal 118 embodied in FIGS. 1A-D is substantiallystraight and extends substantially perpendicular to the secondlongitudinal edge 112. It is appreciated, however, that otherarrangements of the transverse seals 118 are also possible. For example,in some embodiments, the transverse seals 118 have undulating or zigzagpatterns.

The transverse seals 118 as well as the sealed longitudinal edges110,112 can be formed from any of a variety of techniques known to thoseof ordinary skill in the art. Such techniques include, but are notlimited to, adhesion, friction, welding, fusion, heat sealing, lasersealing, and ultrasonic welding. An inflation region, such as a closedpassageway, which can be a longitudinal inflation channel 114, can beprovided. The longitudinal inflation channel 114, as shown in FIGS.1A-D, is disposed between the second end 124 of the transverse seals 118and the first longitudinal edge 110 of the film. The longitudinalinflation channel 114 may extends longitudinally along the longitudinalside 110 and an inflation opening 116 is disposed on at least one end ofthe longitudinal inflation channel 114. The longitudinal inflationchannel 114 has a transverse width D. In the preferred embodiment, thetransverse width D is substantially the same distance as the transversedimension d between the longitudinal edge 110 and second ends 124. It isappreciated, however, that in other configurations other suitabletransverse width D sizes can be used. In some embodiments, the inflationopening 116 includes a one-way valve such as those disclosed in U.S.Pat. No. 7,926,507, herein incorporated by reference in its entirety.

The longitudinal seal 112 and transverse seals 118 cooperatively defineboundaries of inflatable chambers 120. In one preferred embodiment, theinflatable chambers 120 may further include one or more interior seals128. The interior seals 128 may seal the plies 105, 107 to one anotherat intermediate areas within the chamber 120. As shown in FIGS. 1A-D,opposing interior seals 128 may be transversely aligned across thechamber 120. The interior seals 128 may create bendable lines that allowfor a more flexible web 100 that can be easily bent or folded. Suchflexibility allows for the film 100 to wrap around regular and irregularshaped objects.

As shown in FIGS. 1A-1F, interior seal 128 may include a perimeter seal132, which may enclose an inner portion or seal section in which thefirst and second plies 105, 107 are unattached from one another. Theperimeter seal 132 may entirely enclose the inner portion, separatingthe inner portion from the inflation chamber 120. For example, the innerportion may be configured to remain uninflated when the inflationchamber 120 is inflated with the fluid.

The interior seal 128 may be disposed within the inflation chamber 120.For example, the interior seal 128 may be disposed entirely within theinflation chamber 120, and is spaced and unconnected from the boundaries(e.g., 112, 118) of the inflation chamber 120 in which the interior seal128 is disposed. In alternative embodiments, the interior seal 128 maybe connected to a portion of the chamber boundary (e.g., a transverseseal 118 or a longitudinal seal 112). In cases where the interior seal128 is a connected directly by a seal to a transverse seal 118, theinterior seal 128 may be configured so that the inner portion/sealsection 129 is transversely wider than the connection to the transverseseal 118, so that there is a pinched region between the wider area ofthe inner portion 129 and the transverse seal 118. In cases where theinterior seal 128 forms a part of a longitudinal seal 112, the interiorseal 128 may have one or more portions that are substantially wider thanthe connection to the transverse seal 118, so that there is a pinchedregion between the wider area of the inner portion 129 and thetransverse seal 118.

FIGS. 1E and 1F are partial views of FIG. 1C shown along view II-II andview III-III, respectively. In accordance with various embodiments, suchas those illustrated in FIGS. 1E and 1F, interior seal 128 may includean elongated portion 131. The elongated portion 131 may extendtransversely across chamber 120. Additionally or alternatively, theelongated portion 131 may extend longitudinally or in another desireddirection within the chamber 120. In some embodiments, an interior seal128 may include other features, such as two or more perimeter seals 132that enclose inner portions 129, and an elongated portion 131 may extendfrom one of these features to another, such as between perimeter seals132, thus connecting the perimeter seals 132. For example, the twoperimeter seals 132 and the elongated portion 131 may together form a“barbell” shape. As shown in FIGS. 1C and 1D, in some embodiments, aninterior seal 128 may include three perimeter seals 132 that encloseinner portions 129, with the perimeter seals 132 connected to oneanother by two elongated portions 131. Those in the art will appreciatethat an interior seal 128 of other embodiments may include additionalperimeter seals 132 and elongated portions 131 while remaining withinthe scope of this disclosure. FIGS. 1A-1D show chambers 120 havingsimilar interior seal 128 configurations as illustrative examples of thevarious structures discussed herein. For example, a web 100 may have afirst chamber 120 that has a first interior seal 128 having a firstconfiguration (e.g., having a first number of perimeter seals 132 and afirst number of elongated portions 131), and a second chamber 120 thathas a second interior seal 128 having a second configuration (e.g.,having a second number of perimeter seals 132 and a second number ofelongated portions 131). Also, while FIG. 1C shows a chamber 120 havingtwo interior seals 128 having similar configurations, those in the artwill appreciate that a chamber 120 may have a plurality of interiorseals 128 having various configurations (e.g., having varying numbers ofperimeter seals 132 or varying numbers of elongated portions 131) whileremaining within the scope of this disclosure. The web 100 may includeany number of interior seals 128, having any suitable number ofperimeter seals 132 and any suitable number of elongated portions 131disposed within an inflation chamber 120.

The perimeter seal 132 may enclose an inner portion 129 of the plies105, 107. Inner portion 129, defined by the perimeter seal 132, may havea larger width compared to the width of the elongated portion 131. Forexample, the inner portion 129 may be at least 5 times wider than theelongated portion 131. For example, the inner portion 129 may be atleast 10 times wider than the elongated portion 131. For example, theinner portion 129 may be at least 15 times wider than the elongatedportion 131. A solid seal across inner portion 129 (i.e. where the plies105, 107 are attached) may form a stiffer section of the web 100. Anon-solid seal across inner portion 129 (i.e. where the plies 105, 107are unattached) may be a more flexible web 100.

In order to enclose inner portion 129, the interior seal 128 may have atransition. The transition can form an intersection between theperimeter seal 132 and the elongated portion 131, such that theintersection has three leg portions 134 a-c, which are part of theperimeter seal 132 and elongated portion 131. The interior seal 128 mayhave an increased width at the intersection compared to the perimeterseal 132 and the elongated portion 131, to form a gusset 127. The gusset127 may resist localized stresses in the sealed film plies 105, 107. Thegusset 127 may have a width that is wider than the elongated portion131. For example the elongated portion 131 may have a width of J. Thegusset 127 may widen from width J to 1½ times wider to 10 times wider.For example the gusset 127 may be 5 times wider. The gusset may thennarrow again to width K above and below the transition area. The gusset127 may widen to the entire width of the transition area and then narrowback to width J as the interior seal 128 continues. The gusset 127 maybe concave as viewed from the chamber 120. This may allow the transitionto be gradual or not sharp. The gradual transition may reduce stressesat the inner portion 129. A sharp transition may be a stress riser suchas if the inner portion 129 and the elongated portion formed a 90 degreeangle.

FIG. 1E shows a perimeter seal 132 that has two elongated portions 131extending therefrom. For example, as shown in FIGS. 1C and 1D, aninterior seal 128 can include three perimeter seals 132 extendingtransversely, and the middle perimeter seal 132 can include first andsecond elongated portions 131 extending therefrom. The first and secondelongated portions 131 may extend substantially collinear to each other,and/or the elongated portions 131 may extend substantially parallel tothe transverse seals 118. As shown in FIG. 1E, the interior seal 128 mayinclude a second intersection between the perimeter seal 132 and thesecond elongated portion 131, such that the second intersection hasthree second leg portions 134 d-f, which are part of the perimeter seal132 and the second elongated portion 131. The interior seal 128 may havean increased width at the second intersection compared to the perimeterseal 132 and the elongated portion 131, to form a second gusset 127,which may resist localized stressed in the sealed film plies 105, 107.

In accordance with various embodiments, the perimeter seal 128 and/orthe inner portion 129 may be circular, oval, triangular, or any othershape. As shown in FIGS. 1E and 1F, the perimeter seal 128 may becircular and may define an inner portion 129 that is a circle.

In accordance with various embodiments, the plies, walls, structures,etc., discussed herein may be sealed together (e.g., to form interiorseals 128, longitudinal seals 110, 112, and/or transverse seals 118) toform the described structures with any process such as adhesivelybonding, friction, welding, fusion, heat sealing, laser sealing, andultrasonic welding. In various embodiments, an adhesive suitable toconnect separate portions of the materials discussed herein may beutilized. The adhesive may be a pressure sensitive, time dependent,evaluative, radiation sensitive, or other forms of adhesives. Forexample, the adhesive may be cured by exposing the adhesive to anelectromagnetic radiation. The adhesive may be sensitive toelectromagnetic radiations in specific areas of the electromagneticradiation spectrum. For example, the adhesive may be a ultraviolet light(UV) curable adhesive. The adhesives may be applied to the plies, walls,or other structures discussed herein by painting, printing, rolling,etc. An adhesive that is operable to seal the inflation chamberssufficiently to contain gas under shipping pressures may be suitable.These pressures may be those formed by stacking the flexible structureunder multiple layers of the shipped product or other environmentalpressures on the flexible structure internal or external that wouldoccur during shipping, storage, or use. As discussed herein any of theseals may be made by just heat sealing, just adhesive sealing, bothtypes of sealing, or any other type of sealing.

In accordance with various examples, the plies 105, 107 may be sealedtogether forming an interior inflation chamber according to any suitablemethod. Furthermore, the flexible structure 100 already formed of plies105, 107 may be sealed to itself or another portion of flexiblestructure 100 in order to form specific structures such as for examplecontainer 50 (see FIGS. 12A-B).

As shown in FIGS. 12A-B, each separate flexible structure (e.g. 100) maybe utilized to form a container 50. FIGS. 12A-B show a c-fold structureas one example of forming container 50. For example, the container 50may be formed by sealing two separate flexible structures 100. Thecontainer 50 may be structured from any number of sheets of flexiblestructure 100 forming more than two walls as the various applicationdictates. FIG. 12A illustrates a schematic of the flexible structurebeing folded in accordance with various embodiments. As discussed above,the flexible structure 100 may be folded along intermittent seal 153.This intermittent seal may be anywhere and in any number, such thatflexible structure 100 may be folded with any number of folds. Invarious embodiments, the flexible structure 100 may be folded along thecenterline as illustrated in the example of FIG. 12A. Folding theflexible structure 100 in this way may allow the edges 102,106 and104,108 to align. With the flexible structure 100 folded, the first walland the second wall may be sealed along a plurality of seals. Forexample, as illustrated in FIG. 12B, these seals may include one or moreof top seal 145, external longitudinal seal 142, internal longitudinalseal 141, and bottom seal 159. A second transverse seal similar to theseal 145 may additionally be formed along the transverse edge 149. Thesecond transfer seal may be an alternative seal to seal 145. In someembodiments, the container may include handles 50, which may also besealed together at 150. These seals may be made after produce, or othercontent, has been placed in the container 50. The seals may be made withmechanical attachment (e.g. zip style), with heat, with an adhesive, orany other way known in the art. The first wall and the second wall ofthe container 50 may be sealed along adhesive seals shown in FIG. 12A.For example, seals on the first wall 50 a may include one or more of 141a, 142 a, 159 a, 150 a and 145 a. Seals on the second wall 50 b mayinclude one or more of 141 b, 142 b, 159 b, 150 b and 145 b. The sealsmay form the boundary around an unattached portion defining the interior147 of the container 50. The interior 147 may receive the produce orother content. Seals 141 a, 142 a, 159 a, 150 a 145 a, 141 b, 142 b, 159b, 150 b and 145 b are operable to connect walls which are made up ofmultiple plies of film. Thus these seals do not necessarily extendbetween plies 105, 107 but may do so. This seals may extend merely frompile 105 to ply 105 or ply 107 to ply 107, thus forming walls of thecontainers. It should be noted that in situation in which an adhesive isused, it may be placed on each of the “a” and “b” locations, such as 141a and 141 b for example. However it may be placed on only one of theselocations such as 141 a and when the structure 100 is folded 141 a mayalign with 141 b such that he seal is formed in both locations. This mayapply to 142 a,b 159 a,b and 145 a,b as well.

The plies 105, 107 or similar structures may be heat-sealed together.Alternatively the plies 105, 107 may be adhesively sealed together witha UV curable adhesive. The UV curable adhesive may be applied to one orboth plies 105, 107, the plies may then be laid over top of one anotherand then sealed together by applying an ultraviolet light. In variousembodiments, the adhesive may be printed onto one or both plies 105, 107to form the various designs, patterns, or like that make up the internalstructures such as the air chambers. The UV curable adhesively sealedplies 105, 107 may be folded over to form separate walls of container50. The separate walls may also have a UV curable adhesive printedthereon and then be sealed together with the UV light to form thecontainer 50. After forming the container 50, the inflation chambersformed between plies 105, 107 may be inflated and sealed off via heatsealing to keep the chambers inflated.

A series of lines of weaknesses 126 is disposed along the longitudinalextent of the film and extends transversely across the first and secondplies of the film 100. Each transverse line of weakness 126 extends fromthe second longitudinal edge 112 and towards the first longitudinal edge110. Each transverse lines of weakness 126 in the web 100 is disposedbetween a pair of adjacent chambers 120. Preferably, each line ofweakness 126 is disposed between two adjacent transverse seals 118 andbetween two adjacent chambers 120, as depicted in FIGS. 1A-D. Thetransverse lines of weakness 126 facilitate separation of adjacentinflatable cushions 120.

The transverse lines of weakness 126 can include a variety of lines ofweakness known by those of ordinary skill in the art. For example, insome embodiments, the transverse lines of weakness 126 include rows ofperforations, in which a row of perforations includes alternating landsand slits spaced along the transverse extent of the row. The lands andslits can occur at regular or irregular intervals along the transverseextent of the row. Alternatively, for example, in some embodiments, thetransverse lines of weakness 126 include score lines or the like formedin the web material.

The transverse lines of weakness 126 can be formed from a variety oftechniques known to those of ordinary skill in the art. Such techniquesinclude, but are not limited to, cutting (e.g., techniques that use acutting or toothed element, such as a bar, blade, block, roller, wheel,or the like) and/or scoring (e.g., techniques that reduce the strengthor thickness of material in the first and second plies, such aselectromagnetic (e.g., laser) scoring and mechanical scoring).

In accordance with various embodiments, the inflatable flexiblestructure may be usable with variety of inflation and sealing devices.As an example, turning now to FIG. 2, an inflation and sealing device101 for converting a flexible structure such as web 100 of uninflatedmaterial into a series of inflated pillows or cushions 120 is provided.As shown in FIG. 2, the uninflated web 100 can be a bulk quantity ofsupply, uninflated material. For example, the bulk quantity ofuninflated material may be a roll of the material 134 as illustrated inFIGS. 2 and 3. The web 100 may be rolled around an inner support tube133.

The inflation and sealing device 101 may include a bulk material support136. The bulk quantity of uninflated material may be supported by thebulk material support 136. For example, the bulk material support may bea tray operable to hold the uninflated material, which tray can beprovided by a fixed surface or a plurality of rollers for example. Tohold a roll of material the tray may be concave around the roll or thetray may convex with the roll suspended over the tray. The bulk materialsupport may include multiple rollers which suspend the web. The bulkmaterial support may include a single roller that accommodates thecenter of the roll of web material 134. As illustrated in FIGS. 2-4, theroll of the material 134 may be suspended over the bulk material support136, such as a spindle passing through the core 133 of the roll of thematerial 134. Typically, the roll core is made of cardboard or othersuitable materials. The material support 136 may rotate about an axis Y.

The web 100 may be suspended over a guide 138 after being pulled off ofthe supply of uninflated material (e.g., roll 134). The guide mayprovide support to the web 100 upon a transition from the bulk quantityof uninflated material to the sealing and inflation mechanism 103. Theguide may be a stationary rod extending from a support member 141. Theguide 138 directs the web 100 away from the bulk quantity of uninflatedmaterial (e.g. roll 134) and steadily along a material path “B” alongwhich the material is processed in a longitudinal direction “A”. As thebulk quantity of uninflated material may change position or dimension asthe web 100 is continuously pulled from it (e.g. the roll 134 maydecrease in diameter as material is pulled off), the guide may maintainalignment with the sealing and inflation mechanism despite thesechanges, and preferably with the upstream end of inflation tip 142. Theguide 138 can be configured to limit the material 134 from saggingbetween the inflation nozzle 140 and roll 134, and can help maintain anydesired tension in the web 100 of the material.

FIG. 4 illustrates a view of the inflation and sealing device 101 alongaxis Y. The material support 136 is shown on its end, and the length ofthe guide 138 is shown in an isometric view illustrating an angulardifference between the two. FIG. 5 illustrates a front view showing theend of guide 138 but a bottom isometric view of material support 136. Inaccordance with embodiments discussed herein, the material support 136and the guide 138 may rotate around axes Y and X respectively. The axisX may be perpendicular to the support member 141 with Y beingnon-perpendicular to the support member 141.

In accordance with various embodiments, the web 100 may travel throughthe inflation and sealing device 101 along path E. As illustrated inFIGS. 3 and 4, the film path E extends along the nozzle 140. An axis Zis located where the film path E follows the nozzle 140. In accordancewith various embodiments, the direction that nozzle 140 points is thesame direction axis Y points. For example if nozzle 140 points up (e.g.away from base 183) then axis Y points up. If nozzle 140 points down(e.g. toward base 183) then axis Y points down.

In various embodiments, the web 100 may pass above the guide 138. Insuch embodiments, the material support 136 and axis Y may be angled withrespect to guide 138 such that the material support 136 and axis Y pointin the same direction as the web 100 passes over guide 138. If web 100passes over guide 138 then the material support 136 may point uprelative to the guide 138. If web 100 passes under then guide 138, thenthe material support 136 may point down relative to guide 138.

In accordance with various embodiments, the web 100 passes through theinflation and sealing assembly 103 and extends away from the inflationand sealing device 101 in a transverse direction which is perpendicularto longitudinal direction A in which the web 100 exits the inflation andsealing device 101.

When the web 100 is removed from the material support 136 and ispositioned at an angle different from the guide 138, the web 100includes a slight twist as it is removed from the bulk quantity ofuninflated material (e.g. roll 134) and re-aligned over and in contactwith guide 138. The web 100 may roll off of material support 136tangentially and thereby forming a plane (or a surface that approximatesa plane tangential with the surface of the roll 134) that is parallelwith the axis of material support 136. The web 100 may also engage guide138 tangentially forming a different plane (or approximating a differentplane tangent with the guide 138). The web may merely reflect tangentialplanes as if it maintained tangential contact with the material support136 or guide 138 even if in practice there is tension on one transverseend of the web 100 and slack on the other transverse end of the web 100.In order to accommodate both tangential contacts the web 100 may realignor twist slightly between the material support 136 and guide 138.

In accordance with various embodiments, the nozzle 140 may inflate web100 not only at a transverse edge but may engage an inflation channellocated at any transverse distance between the longitudinal edges; i.e.,the inflation and sealing device 101 fills a central channel withchambers on both transverse sides of the inflation channel. The web 100may roll off of material support 136 and over guide 138 in a manner thataligns such a central inflation channel with the nozzle 140.

In various embodiments the material support 136 may include a spindle200. The spindle 200 may be axially aligned along axis Y with a motor220. The motor 220 and the spindle 200 may be attached via a bulkheadconnector 222. The bulk head connector 222 may have a mounting surface223. The mounting surface may attach to the backside of the supportmember 141 such that the motor 220 may be positioned on one side and thespindle 200 may be positioned on the other side as illustrated in FIG.6. The mounting surface 223 may form an angle with axis Y such that axisY is not perpendicular thereto. For example, FIG. 6 shows mountingsurface 223 as parallel with vertical plate 184. As such, λ representsthe angle between mounting surface 223 and Y. Instead, the mountingsurface 223 may be angled such that as it attaches to the back side ofthe support member 141, it tilts the spindle 200 and motor 220 relativeto the support member 141. An example of this structure is shown in FIG.6 with the angle λ which may also represent the angle between mountingsurface 223 and the axis Y. Spindle 200 may be supported within the bulkhead connector 222 by bearings 214 and 224. The bearings 214,224 mayallow the spindle 200 to be rotatable independent of the bulkheadconnector 222 and ultimately the support member 141, to which thebulkhead connector 222 attaches. In various embodiments, the spindle maybe supported on a shaft, surface bearings, or by the motor directly. Thespindle 200 may be locked into place on the bulk head 222 with clip 226.Cover 228 and bulk head connector 222 may form an enclosure around motor220.

The spindle 200 may include two sections, a body portion 202 and a tipportion 204. The body portion 202 and the tip portion 204 may be formedof different materials. 6. The spindle 200 preferably has core supportportions 206, which are outwardly facing surfaces spacedcircumferentially about axis Y from each other to provide radiallyrecessed areas 208 therebetween. The core support portions 206 protruderadially from the axis Y higher than the surfaces of the spindle 200 inthe radially recessed areas 208. The core support portions cancollectively define and be positioned along a phantom cylindricalsurface that will correspond closely to the interior, hollow, surfacewithin a supply roll 134. If other shaped cores are to be used, the coresupport portions can be arranged in other shapes. The core supportportions 206 can be curved circumferentially along this phantomcylindrical surface or can be flat or have other shapes. The recessedareas 208 are positioned radially inward of the phantom cylinder, sothat they entirely or in large part do not contact the interior of asupply roll mounted on the spindle 200. The recessed areas 208 havesubstantially flat surfaces in the embodiment shown, but otherconfigurations can be used.

In the embodiment of FIG. 7, the recessed areas 208 lie below thephantom cylinder 207, and the core support portions 206 generally followthe phantom cylinder 207, although other shapes can be used. In thismanner, the spindle 200 may be generally triangular in shape havingthree core support portions 206, but can alternatively have four, five,or more core support surfaces, and the core support portions can beevenly or unevenly distributed circumferentially about the spindle. Inone example, as shown in FIG. 8 viewed down the Y axis, the spindle 200may have an axial cross section that forms a triangle. The core supportsurfaces 206 preferably extend substantially axially with respect to thespindle (transversely with respect to the material path or machinedirection in the embodiment of FIG. 2) to help in sliding a web rollcore 133 on and off the spindle.

By providing the recessed areas between the core support portions 206provides the spindle with a discontinuous support surface in which thecontact area it has with a core 133 of a supply web roll 134 can bereduced compared to traditional, continuous-surface cylindricalspindles. This reduces the friction between the spindle 200 and core133, allowing the core 133 to be more easily inserted and slid off fromthe spindle 200. Additionally, as is common and can be seen in FIG. 4,the core 133 can be deformed, such as by damage during shipping of thesupply material roll 134. Damaged, out-of-round cores can be verydifficult or impossible to insert onto a fully cylindrical spindle. Therecessed areas 208 on the discontinuous spindle surface can accommodatedeformations of the core 133 that extend inwardly between the coresupport portions 206, allowing dented or flattened cores to remainuseable. In this way, the core support surfaces 206 a,b,c or a pluralityof grip elements 210 which extend from the core support surfaces 206a,b,c, may contacts or occupy only a fraction of the outer core surfacecircumference. The plurality of contacts may contact a finite number ofpoints within an internal surface of a hollow tube onto which the web ofmaterial is rolled. In various examples, the plurality of grip elements210 may extend beyond the generally cylindrical shape shown by line 207.The plurality of contacts may form a larger diameter around the spindlethan the size of the inner diameter of inner support tube 133. Thisstructure would allow the plurality of contacts to engage in aninterference fit with the core 133 while the minimized outer cylindricalsurface segments 206 a,b,c minimize other contact within the core 133.Preferably, the grip elements 210 are biased outwardly and areresiliently movable inwardly into the spindle 200. Such bias can beprovided by springs within the spindle. The outer surface of the gripelements 210 can be spherical, conical, or have another shape thatpreferably facilitates sliding of the core 133 during loading andunloading on or from the spindle, and that grips the inner surface ofthe core 133 during use, to help transfer torque from the spindle to theroll, and preferably from the brake 137, described below. A chamfer 204at the end of tip portion 204 may additionally reduce the effort ofinserting spindle 200 into the inner support tube 133.

Referring back to FIGS. 2-6, the support element 136 may be connectedwith a brake 137. The brake 137 may prevent or inhibit bunching up ofthe web material 100 and maintain a desired tension in the web material100 as it is unwound from the roll 134 and as it is fed onto and/or intothe inflation and sealing mechanism. The brake 137 may prevent orinhibit release of the bulk uninflated material from the support 136.For example, the brake 137 may inhibit the free unwinding of the roll134. The brake may also assure that the roll 134 is unwound at a steadyand controlled rate. The brake 137 may be provided by any mechanism thatprovides control. For example, according to one embodiment, aspring-loaded leather strap or other friction mechanism can be used as adrag brake on the bulk material support 136. In another embodiment, thebrake 134 may be an electric motor or other actuator used to provideresistance to the rotation of the bulk material support 136 as the roll134 is unwound. As shown in FIGS. 7-8, the support element 136 isspindle 200 which is axially connected to a brake which may operate as aresistance mechanism. The resistance mechanism resists rotation of thesupport element 136 (e.g. spindle 200). The resistance mechanism may bemotor 220 which controls rotation of the spindle 200, therebycontrolling advancement of the web 100 by either positively drivingrotation of spindle 200 or retarding the rotation of spindle 200. Byretarding the rotation of spindle 200, the brake can also increasetension on the twisted web proximal to the support member 141,maintaining proper alignment with the inflating/sealing mechanism.

Preferably, the inflation and sealing device 101 is configured forcontinuous inflation of the web 100 as it is unraveled from the roll134. The roll 134, preferably, comprises a plurality of chain ofchambers 120 that are arranged in series. To begin manufacturing theinflated pillows from the web material 100, the inflation opening 116 ofthe web 100 is inserted around an inflation assembly, such as aninflation nozzle 140. In the embodiment shown in FIG. 2, preferably, theweb 100 is advanced over the inflation nozzle 140 with the chambers 120extending transversely with respect to the inflation nozzle 140 andoutlet 146. The outlet 146, which can be disposed on a radial sideand/or the upstream tip of the nozzle 140, for example, directs fluidfrom nozzle body 144 into the chambers 120 to inflate the chambers 120as the web 100 advances along the material path “E” in a longitudinaldirection “A”. The inflated web 100 is then sealed by a sealing drum 166in the sealing area 174 to form a chain of inflated pillows or cushions.

The side inflation area 168 in the embodiment of FIG. 3 is shown as theportion of the inflation and sealing device 101 along the path “E”adjacent the side outlets 146 in which air from the side outlets 146 caninflate the chambers 120. In some embodiments, the inflation area 168 isthe area disposed between the inflation tip 142 and entry pinch area176, described below. The web 100 is inserted around the inflationnozzle 140 at the inflation tip 142, which may be disposed at theforward-most end of the inflation nozzle 140. The inflation nozzle 140inserts fluid, such as pressured air, along fluid path B into theuninflated web material through nozzle outlets, inflating the materialinto inflated pillows or cushions 120. The inflation nozzle 140 caninclude a nozzle inflation channel that fluidly connects a fluid sourcewith the nozzle outlets. It is appreciated that in other configurations,the fluid can be other suitable pressured gas, foam, or liquid. FIGS. 3,9, 10, and 11 illustrates a various view of the inflation and sealingdevice 101. As discussed in various embodiments, the fluid source can bedisposed behind the support member 141 having a horizontal plate 183 andvertical plate 184 or other structural support for the nozzle andsealing assemblies, and preferably behind the inflation nozzle 140. Thefluid source is connected to and feeds the fluid inflation nozzleconduit 143. The web 100 is fed over the inflation nozzle 140, whichdirects the web to the inflation and sealing assembly 103. The web 100is advanced or driven through the inflation and sealing device 101 by adrive mechanism, such as by a driver or sealing drum 166 or the driveroller 160, in a downstream direction along a material path “E”.

In accordance with various embodiments, the nozzle, blower sealingassembly, and drive mechanisms, and their various components or relatedsystems may be structured, positioned, and operated as disclosed in anyof the various embodiments described in the incorporated references suchas for example U.S. patent application Ser. No. 13/844,741. Each ofthese embodiments may be incorporated to the inflation and sealingdevice 101 as discussed herein.

After being fed through the web feed area 164, the first and secondplies 105,107 are sealed together by the sealing assembly and exit thesealing drum 166. The sealing drum 166 includes heating elements, suchas thermocouples, which melt, fuse, join, bind, or unite together thetwo plies 105,107, or other types of welding or sealing elements. Theweb 100 is continuously advanced through the sealing assembly along thematerial path “E” and past the sealing drum 166 at a sealing area 174 toform a continuous longitudinal seal 170 along the web by sealing thefirst and second web plies 105,107 together, and exits the sealing areaat an exit pinch area 178. The exit pinch area 178 is the area disposeddownstream the entry pinch area 164 between the belt 162 and the sealingdrum 166, as shown in FIG. 4. The sealing area 174 is the area betweenthe entry pinch area 164 and exit pinch area 178 in which the web 100 isbeing sealed by the sealing drum 166. The longitudinal seal 170 is shownas the phantom line in FIGS. 1A-D. Preferably, the longitudinal seal 170is disposed a transverse distance from the first longitudinal edge102,106, and, most preferably, the longitudinal seal 170 is disposedalong the mouths 125 of each of the chambers 120.

As shown in FIG. 4, the sealing drum 166 may be arranged above the belt162. The drive roller 160 may be positioned downstream the feed roller158 and tension roller 156 with the sealing drum 166 there between. Thesealing drum 166 may be disposed such that a portion of the sealing drum166 vertically overlaps the feed roller 158, tension roller 156, anddrive roller 160 so that the belt 162 is deformed at the sealing area174 to have a generally U-configuration. Such configuration increasesthe tension of the belt 162 at the sealing area 174, and facilitates thepinching of the web 100 between the sealing drum 166 and the belt 162 atthe sealing area 174. The inflation and sealing assembly 103configuration described also reduces the amount of contact of the web100 during sealing, which reduces bending of the inflated web. As shownin FIG. 7, the contact area is the sealing area 174 between the enteringpinch area 164 and exiting pinch area 174.

In the embodiment shown, the web 100 enters the sealing assembly at theentry pinch area 176 at an angle sloping downward with respect to thehorizontal. Additionally, the web 100 exits the sealing area 174 at anangle sloping upward with the respect to the horizontal so that the web100 is exiting facing upwards toward the user. By having the intake andouttake sloped as described herein, the inflation and sealing device 101allows for easy loading and extracting of the web as well as easy accessto the web. Thus, the inflation and sealing device 101 can be positionedbelow eye level, such as on a table top, without the need of a highstand. The sloping downward intake and sloping upward outtake of the web100 from the sealing assembly provides for the material path “E” to bebent at an angle a between the entry pinch area 176 and the exit pincharea 174 (the entry pinch area 176 and exit pinch area 174 are furtherdescribed below). The angle α between the entry pinch area 176 and exitpinch area 174 is, for example, at least about 40 degrees up to at mostabout 180 degrees. The angle α may be about 90 degrees. Other entry andexit angles can be employed as known in the art in alternativeembodiments.

In accordance with various embodiments, the sealing assembly may beprotected by a removable cover. Likewise, the belt mechanism, e.g. belt162, tension roller 156, and feed roller 158 may also include aremovable cover 173. This allows for a user to easily remove the web orclear up or fix jams within the machine.

In accordance with various embodiments, one or more of the elements ofinflation and sealing device 101 may drive web 100 through the system.For example, the sealing drum 166 may be connected to a motor whichrotates it in a direction “F”. As described in various embodiments (seee.g. application Ser. No. 13/844,741), other elements may also drive thesystem, such as roller 160. In other embodiments discussed in theincorporated references, roller 160 is indicated as a drive roller;however, it may be noted that roller 160 may be either an idler rolleror an active drive roller. For example, roller 160 may be connected tothe same motor or the same drive mechanism associated with the sealerdrum 166 that causes the drum to rotate. In other configurations, thesealing drum 166 may be passive (e.g. an idler) or actively driven by amotor. In one example, the sealing drum 166 may be passive and merely berotated in response to the advancing web 100 or belt 162.

In accordance with various embodiments, the inflation and sealing devicecan have more than one belt. For example one belt may drive the variousrollers and a second belt may pinch the web against the sealing drum. Invarious embodiments, the inflation and sealing device may have no belts.For example the sealing drum may pinch the web against a stationaryplatform and drive the web thorough the inflation and sealing device atthe same time. Additional description and embodiments of such structuresmay be disclosed in U.S. Pat. Nos. 8,061,110 and 8,128,770 andPublication No. 2011/0172072 each of which is herein incorporated byreference.

Although some embodiments do not have a post-seal control element, theinflation and sealing assembly 103 shown in FIG. 2 includes a pluralityof post-seal control elements. In various embodiments, the post-sealcontrol element may be a movable or stationary surface, a roller, or anydevice that can contact the belt 162 or the web 100. For example, apost-seal control element can include roller 160 as discussed above. Theroller 160 supports the web 100 exiting from the inflation and sealingassembly 103 and may be operable to guide the belt. As illustrated inFIGS. 9-11, the roller 172 may also be a post-seal control element. Invarious embodiments, there may be a single post-seal control elementsuch as roller 160 as depicted in embodiments disclosed in theincorporated references (see e.g. Ser. No. 13/844,741). In otherembodiments, there may be multiple post-seal control elements asillustrated in FIGS. 9-11. For example, a first post-seal controlelement (e.g. roller 172) can be disposed directly above a secondpost-seal control element (e.g. roller 160).

The two post-seal control elements (e.g. two rollers 160,172) pinch orpress the web 100 so that the belt 162 abuts one or both of the surfacesof the elements. As the rollers 160,173 are disposed immediatelydownstream of the heating drum (or other heating mechanism in otherembodiments), they provide a cooling region 179 disposed between tworollers 160,172. Roller 160 in this embodiment acts as a principlecooling roller, since the sealed and cooling film is drawn around thisroller 160. Pinch roller 172 maintains the web in contact with theprinciple cooling roller 160 to help maintain the pressure between thetwo film plies as the seal cools to support the seal and surroundingarea mechanically. In embodiments, such as the one shown, in which thebelt 162 extends around roller 160, the outer surface of this rollerremain substantially stationary with respect to the web 100, furtherhelping support the seal in it's delicate state before it has cooledsufficiently. Roller 160 is typically made of a hard and tough material,such as steel or aluminum, to withstand the pressures and heat from thebelt 162, although a plastic or other material could be used in someembodiments.

In various embodiments, the post-seal control element such as roller 172may have a larger-diameter area 171 opposing the belt than in adjacentparts of pinch roller 172. This annular ridge 171 allows contact againstthe web 100, while an adjacent smaller-diameter portion of roller 172can remain out of contact therewith to help prevent sticking to the hotweb. The roller 172 may be biased against the belt 162, web 100, androller 160 by a spring-loaded tensioner 169. The tension provided by thetensioner 169 may further hold the seal closed by the post-seal controlelement, and can allow the pinch roller 172 to be lifted off the webwhen needed.

To prevent or reduce sticking of the hot web 100 to the pinch roller172, the pinch roller is preferably made of, or has a surface of, anon-stick or low adhesion material such as polytetrafluoroethylene(PTFE) or other suitable material as discussed below. In accordance withvarious embodiments, the post-seal control element such as roller 160may include a recessed annular surface 163. The recessed annular surface163 may receive the belt 162.

When the web exits pinch area 178 between rollers 160 and 172 (these tworollers 160, 172 are at the exit of the sealing mechanism, such as thedownstream exit from the device) there is a possibility that the hotfilm will stick to one of these rollers instead of cleanly exiting thedevice. In various embodiments, an element can be provided to helpseparate the film from the post-seal control elements. For example,roller 172 can have an annular ridge 161 extending proud the belt 162 orouter surface 167 of the roller 160 that supports the belt 162 againstthe web 100, or that contacts the web 100. This ridge 161 can be annularor have another suitable shape and can run around the roller to contactthe web 100, preferably transversely adjacent the longitudinal seal onthe inflated web 100, such as against the transverse end of the inflatedchambers 120 adjacent the longitudinal seal 112. At the pinch area 178,the annular ridge 161 contacts the web 100, typically against atransverse side of the inflated chambers 120 where due to the inflatedshape, the chambers 120 have a degree of rigidity compared to theuninflated film. The elevated ridge provides a bump-off element thatforcing the web 100 to deflect off the roller 160. The annular ridge 161is a second surface that causes the web to bend. The bend may cause aportion of the web 100, located in the lateral direction relative to afirst portion of the web 100 that is pressed between the first post-sealcontrol element (e.g. roller 172) and the second post-seal controlelement (e.g. roller 160), to not stay in the same plane as the firstportion of the web. Forcing different portions of web 100 into differentplanes may cause the web 100 to unseat, and often unstick, from the beltand/or the roller 160. As such, the annular ridge 161 aids inautomatically peeling the web 100 off the post-seal control elements.While described with respect to a roller, alternative embodiments canhave a stationary ridge provided adjacent the roller 160 to guide theweb off the cylinder.

As the heated web 100 may have a tendency to stick to the post-sealcontrol elements, non-stick materials may mitigate this issue. Forexample, one or both post-seal control elements may be made from ofcoated with polytetrafluoroethylene (PTFE), anodized aluminum, ceramic,silicone, or like non-stick/low-adhesion materials.

In the embodiments shown, the inflation and sealing device 101 furtherincludes a cutting assembly 186 to cut the web off the inflation nozzlewhen an inflation channel that receives and is closed around alongitudinal inflation nozzle 140 is used. As with other systemcomponents discussed herein, the cutting assembly may also bestructured, provided, or included in accordance with the variousembodiments described by the incorporated references discussed above.

While the inflatable packaging product 100 may be formed using thedisclosed inflation and sealing device 101, the inflation and sealingdevice is exemplary, and it should be well understood that other devicescan be used to form the inflatable packaging product 100, instead of orin addition to the sealing device 101.

Any and all references specifically identified in the specification ofthe present application are expressly incorporated herein in theirentirety by reference thereto. The term “about,” as used herein, shouldgenerally be understood to refer to both the corresponding number and arange of numbers. Moreover, all numerical ranges herein should beunderstood to include each whole integer within the range. The contentof U.S. patent application Ser. No. 13/844,741 is hereby incorporated byreference in its entirety. While useful features of the disclosure arediscussed above, it will be appreciated that such features can beprovided in ornamental arrangements on a web material.

While illustrative embodiments of the invention are disclosed herein, itwill be appreciated that numerous modifications and other embodimentsmay be devised by those skilled in the art. For example, the featuresfor the various embodiments can be used in other embodiments. Therefore,it will be understood that the appended claims are intended to cover allsuch modifications and embodiments that come within the spirit and scopeof the present invention.

What is claimed is:
 1. An inflatable flexible structure, comprising: afirst film ply; a second film ply that is sealed to the first ply todefine an inflation chamber therebetween that is inflatable with a fluidand operable to contain the fluid; and an interior seal disposed withinthe inflation chamber attaching the first and second plies together, theinterior seal including a perimeter seal that encloses an inner portionin which the first and second plies are unattached from one another. 2.The inflatable flexible structure of claim 1, wherein the perimeter sealentirely encloses the inner portion, separating the inner portion fromthe inflation chamber.
 3. The inflatable flexible structure of claim 1,wherein the interior seal is disposed within the inflation chamber. 4.The inflatable flexible structure of claim 3, wherein the interior sealis disposed entirely within the inflation chamber.
 5. The inflatableflexible structure of claim 1, wherein the interior seal includes afirst elongated portion extending from the perimeter seal.
 6. Theinflatable flexible structure of claim 5, wherein the interior sealincludes another perimeter seal, and wherein the first elongated portionextends from the perimeter seal to the other perimeter seal.
 7. Theinflatable flexible structure of claim 5, wherein the interior sealincludes an intersection between the perimeter seal and the elongatedportion, such that the intersection has three leg portions which arepart of the perimeter seal and the elongated portion, the interior sealhaving an increased width at the intersection compared to the perimeterseal and elongated portion, thereby forming a gusset that resistslocalized stresses in the sealed film plies.
 8. The inflatable flexiblestructure of claim 7, wherein the interior seal includes a secondintersection between the perimeter seal and a second elongated portion,such that the second intersection has three second leg portions whichare part of the perimeter seal and the second elongated portion, theinterior seal having an increased width at the second intersectioncompared to the perimeter seal and second elongated portion, therebyforming a second gusset that resists localized stresses in the sealedfilm plies.
 9. The inflatable flexible structure of claim 8, wherein thefirst elongated portion extends from the perimeter seal to a secondperimeter seal, and wherein the second elongated portion extends fromthe perimeter seal to a third perimeter seal.
 10. The inflatableflexible structure of claim 5, wherein the inner portion is at least 10times wider than the elongated portion.
 11. The inflatable flexiblestructure of claim 1, comprising a plurality of said interior seals. 12.The inflatable flexible structure of claim 1, wherein the first andsecond plies are sealed to one another to define a plurality ofinflation chambers therebetween, the plurality of inflation chambersincluding the inflation chamber and a second inflation chamber.
 13. Theinflatable flexible structure of claim 12, wherein the second inflationchamber includes a second interior seal attaching the first and secondplies together, the second interior seal including a second perimeterseal that encloses a second inner portion in which the first and secondplies are unattached from one another.
 14. The inflatable flexiblestructure of claim 1, wherein the inner portion is configured to remainuninflated when the inflation chamber is inflated with the fluid. 15.The inflatable flexible structure of claim 1, wherein the first andsecond plies are heat sealed together to form the interior seal.
 16. Theinflatable flexible structure of claim 1, wherein the first and secondplies are sealed together with an adhesive to form the interior seal.